Sciadopitys verticillata, the kōyamaki or Japanese umbrella-pine, is a unique coniferendemic to Japan. It is the sole living member of the family Sciadopityaceae and genusSciadopitys, a living fossil with no close relatives. The oldest fossils of Sciadopitys are from the Late Cretaceous of Japan, and the genus was widespread in Laurasia during most of the Cenozoic, especially in Europe until the Pliocene.[2] An extinct European relative of this species may have been the primary producer of Baltic amber.
Taxonomy
Molecular evidence indicates that Sciadopityaceae is the sister group to a clade comprising Taxaceae and Cupressaceae, and has an extremely ancient divergence, having diverged from the rest of the conifers during the early mid-Permian.[3]
There is inconsistent evidence regarding the plant family which produced Baltic amber. Both macrofossil and microfossil evidence suggest a Pinus relative, whereas chemical and infrared microspectroscopy evidence suggest relatives of either Agathis or Sciadopitys.[4][5]
Etymology
The genus name Sciadopitys comes from Greek sciádos (σκιάδος) meaning 'umbrella' and pitys (πίτυς) meaning 'pine'.[6] The species name verticillata is a descriptive epithet meaning 'whorled'.
Description
It is an evergreentree that can grow 15–27 m tall, with brown main shoots bearing whorls of 7–12 cm long flexible green cladodes that look like, and perform the function of, leaves, but are actually composed of stem tissues. The cones are 6–11 cm long, mature in about 18 months, with flattish scales that open to release the seeds.[citation needed]
A stylized representation of the tree (known in Japanese as kōyamaki) was chosen as the Japanese Imperial crest for the Akishino branch of the Imperial Family.
Gallery
Sciadopitys carpellate cones and dried needles
Staminate cones and needles
Needles
Full tree in Mount Futatsumori, Nakatsugawa, Gifu Prefecture, Japan
^Weitschat, W.; Wichard, W. (2010). "Chapter 6: Baltic amber". In Penney, D. (ed.). Biodiversity of Fossils in Amber from the Major World Deposits. Siri Scientific Press. pp. 80–115. ISBN978-0-9558636-4-6.